Official Test Results: Five Ways to Heat a Tent

[jacobconroy]

I have been revisiting this problem too, due to the weather. Truth be told, it is much cheaper and easier to invest in a second sleeping bag.

Not trying to be a jerk. I have truthfully found that warmer sleeping gear is preferable to expensive, esoteric heating options that "usually" work.

I have a Propex sitting in the garage. So, I'm not being cheap.

 

[MattJ]

Curious if you tested the conduit itself for leaks? Not sure if that stuff is “ watertight”.

The exhaust chugs out at a constant rate but without much pressure, so I just need to give it some help getting away from the tent. The conduit solution fits very tight and snug, plus it is 100% metal. I've learned the hard way that even high-heat silicone and ducting can melt due to the extreme heat of the exhaust. I'm not sure if the conduit is waterproof, airtight or pressure-capable, but I don't think it needs to be any of those. Just needs to get the monoxide a few feet away and not melt. I've learned there is some condensation that builds up in the exhaust pipe too, so it's important that it runs downhill. But thanks for your question and observation!

I have been revisiting this problem too, due to the weather. Truth be told, it is much cheaper and easier to invest in a second sleeping bag.

Yeah, I know. But I got obsessed with figuring out how to design the perfect insulation system for the air intake, heat output and exhaust. All the failed attempts just made me more determined to figure it out. And I convinced myself that a durable, portable, well-made heating kit with extension hoses might come in handy someday for other uses. Such as heating a sleep-in trailer or ice fishing hut or Tentipi or a Hilleberg expedition tent or . . .

Anyway, I did a test-run in the driveway today. Everything worked great. I made a carrying case that doubles as a rain-proof cover. I couldn't fit the largest hose into the case, but at least it fits on top of the case on my Jeep cargo rack.

 

[john61ct]

I have a Propex sitting in the garage.

Happy to help you de-clutter

Heat while sleeping, completely agree.

But the ability to get the living space toasty while working, reading, playing on screens etc can make a huge difference.

Especially for full-timing when heading south is not an option.

 

[MattJ]

Some more testing today. Results:

1) Exhaust port gets to 160F
2) Flexible conduit exhaust pipe is NOT waterproof, but it does route the CO2 away from the unit. Condensation leaks out as the exhaust cools.
3) Temperature of output air appears to be 110F

Field test this weekend! Forecast is for 30F and plenty of rain and precipitation . . .

 

[jacobconroy]

You fellows are right...I'm going to keep the Propex. I slept in there the other night without heat and it was just fine...until the dreaded 4 AM shivers! Getting out of that sleeping bag in the morning is a chore without the old Propex.

 

[Victorian]

Protect yourself from toxic fumes and use heat ducting that's designed for high heat. It looks like you are using shop vac hoses. They will outgas a toxic mess when hot!!!!

 

[MattJ]

You fellows are right...I'm going to keep the Propex.

Can you post some pictures of your set up? Are you using it with a roof top tent?

Protect yourself from toxic fumes and use heat ducting that's designed for high heat. It looks like you are using shop vac hoses.

Thanks for the advice! The output hose is reflective high-heat ducting, made in the U.K. and sold as a component to the Propex kit. The outer layer is a sepearate thermoplastic tubing, also sold with the kit. I had to make extensions since the kit only comes with very short ducting. I posted the specs back on page 5 of this thread but here they are again. These materials should withstand the 110-125F output heat, correct? I've been working on this project for two years and $2,500, so I want to get it right!

 

[Fording]

As someone who really only has time off in the winter for any kind of camping or overland opportunities, thank you. I’m getting older and comfort/roughing it are starting to blur together. Thank you to all who have helped with this thread and provided ideas.

Right now I’m running a triple battery bank (300 ah), electric blanket, and the winter cover on my CVT. Anything under 25*F and it’s annoying.

Matt... awesome job. I’ll probably end up borrowing your general design idea with tweaks for my application. An 8’ truck bed is definitely convenient.

 

[jacobconroy]

Can you post some pictures of your set up? Are you using it with a roof top tent?

I used to use the Propex in a second-hand Adventure Trailers "toolbox" with the Jeep. But, the Jeep has been decommissioned and I'm preparing to install the heater in a van.

 

[MattJ]

Here we go . . . notes from a weekend field test! Some good news and some bad news, just like every field test . . .

Weather was 30F to 40F with constant precipitation (sleet, ice and rain). Wonderful weather for spending a weekend in a roof top tent, especially when packing up for off-road trail runs every day.

The good news:
1) Lining my tent with reflective emergency blankets worked great. It took less than five minutes to do it, and I think it dramatically changed the heat retention profile of the tent space (yes, I was careful NOT to cover the air vent soffits on either side). I'm thinking I should find a tailor shop that can cut and sew reflective blankets into roof top tent liners with Velcro attachment straps and sell them for profit!

2) I also tested a single UCO candle, which appeared to boost the air temperature in the tent as much as 10 degrees when combined with my own body heat. I have a 3-candle UCO lantern that I want to try next. I bet it helps dry out the air in wet conditions, too.

3) On the first night, the Propex system worked GREAT. It was 70F in my tent, and the heater cycled on/off several times during the night to refill my tent with warm, dry air. The insulated hoses I built worked perfectly.

The bad news:
1) The heater failed when I was getting dressed in the tent on the second morning. Thinking this was the "stuck valve" problem I had on my last field test, I shook the propane tank and banged it with the rubber mallet I packed for just this reason. Sure enough, the heater ignited perfectly on the next cycle. In case I needed to do the same trick again on the second night, I mounted the tank on a platform within reach of the tent window.

2) But during the second night, the heater would not light. I shook the propane tank, hoping to unstick the valve, but it didn't help. I decided not to bang it with the rubber mallet since there were others sleeping in tents around me. Fortunately, I had packed warm sleeping clothes and a 15F sleeping bag as my backup plan.

3) The next morning, there was PLENTY of tank banging and shaking, but still no luck getting the heater to light. And worse, when I got home and tried two other tanks . . . no lighting. I can see the hose pressurize and smell the puff of propane as it tries to light, so I am convinced there is a failure with the sparking mechanism. I am facing the chore of more hours invested in this heater project to troubleshoot this problem, which won't be easy. But then again, this crazy project was never about "easy" in the first place . . .

 

[jacobconroy]

Lol, sounds like a life spent playing with a Propex. I feel your pain brother.

To be fair, most of the time I haven't been able to get my Propex to work it was because I was half-in-the-bag when I set it up. Finally found out that one time I had set it in a place that blocked one of the combustion hoses (but not until I got home and looked up the error code). Another time there was an intermittent connection inside the unit (which tooks a month of weekends to pin down). One time my propane tank was empty. It's always something. I wonder if it is because the unit is in a portable "tool box"? Too much moving, connecting, and changing?

Do the VW guys that have a Propex permanently installed have the same flaky behaviors?

These heaters are awesome when they work, but in my experience, you'd best not count on them.

 

[MattJ]

These heaters are awesome when they work, but in my experience, you'd best not count on them.

Amen to that. I've learned that the more complicated a piece of gear it is, the more necessary it is to have Plan B packed too. Not only do I have to haul the Propex kit, 15 feet of hoses and a propane tank, I also need a 15F sleeping bag and several layers of sleeping clothes. It's more than a bit ridiculous, but that first night in a 70F tent with sleet falling outside was VERY nice.

I tracked down the phone number for the Propex rep here in the United States, so hopefully he can help me troubleshoot my heater.

 

[chet6.7]

2) I also tested a single UCO candle, which appeared to boost the air temperature in the tent as much as 10 degrees when combined with my own body heat. I have a 3-candle UCO lantern that I want to try next. I bet it helps dry out the air in wet conditions, too.

This youtuber has two videos on the 3 candle UCO,one stock,apparently they put out 5K BTU's and the video I linked.

 

[MattJ]

This youtuber has two videos on the 3 candle UCO,one stock,apparently they put out 5K BTU's and the video I linked.

Thanks - I watched the conversion video and the one where he tested the 3 and 1-candle UCO lanterns at the same time. Made me wonder if 3 single-candle lanterns dispersed around the tent would be better than a single 3-candle lantern.

 

[chet6.7]

I suspect the heat/light would be more evenly dispersed,maybe even have them placed at different levels to minimize stratification,a muffin fan might help as well.